Quartz vs. Fused Silica: What’s the Difference?

If your project demands high performance material, you may have more options than you think. Quartz, Fused Quartz and Fused Silica are all part of an extremely pure family of materials with high working and melting temperatures and superior optical properties as well as low coefficient of expansion.

While they’re often used interchangeably, the fundamental structures and creation of quartz and fused silica are different. Both are highly specialized, but their particular performances vary.

Quartz

Quartz is a very versatile, naturally occurring substance with good electrical, optical and thermal performance and corrosion resistance. In production, quartz glass or fused quartz is created from grains of natural material that are melted and purified.

Key Traits

Fused Silica

Fused Silica is an entirely synthetic material, and is technically the purest glass. It has the highest temperature characteristics of any glass, and it often begins as pure silicon gas. Because of the way fused silica is made, it has superior ultraviolet performance to natural quartz and is ideal for applications such as UV transmitting optics.

Key Traits

Crafted from silicon gas or silica sand (non-crystalline)

Amorphous

Cross-linked, 3D structure

Significant transparency into deep ultraviolet

Retains some residual impurities from water vapor in processing (affects infrared transparency)

High Performance Materials at Swift Glass

Both of these materials are ideal for semiconductor fabrication, technical and laboratory equipment. Distinctive features they share include:

Extremely low coefficient of expansion (very shock resistant)

Extremely high temperature resistance

Exceptional optical transmission

The Swift Glass Team specializes in custom work, and we’re proud to maintain a vast material inventory. Having a wide range of choices makes it easy to find the perfect glass for your next project, but it also requires careful consideration and attention to subtle qualities.

Remember to evaluate the key traits you need, even once you’ve narrowed your search to a high-performance material:

Thickness

Normal Service Temperatures

Extreme Service Temperatures

Maximum Temperature, Thermal Shock

Maximum Temperature, Thermal Gradient

In/In/F Coefficient of Thermal Expansion

We stock a range of quartz and fused silica glasses from different manufacturers, each with its own particular strengths. Check our online resources and eBooks to learn more, or call the team for more insight —we’ll find just the right glass for your next project.